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This is an MRI of the brain

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in a one-year-old child

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with neurofibromatosis type 1.

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We're not seeing any significant

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areas of myelin vacuolization.

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We're not seeing any focal lesions.

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And so, at first glance,

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we're not really seeing anything abnormal

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or concerning, and that's not unusual.

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We perform these studies for surveillance.

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Several years later,

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the patient was three-years-old

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and presented with vocal cord paralysis.

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Well, at that time,

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we're starting to see some areas

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of myelin vacuolization,

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but those won't cause a vocal cord paralysis.

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We're seeing some signal abnormality in the

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region of the uncus of the temporal lobe,

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in the brainstem, here in the midbrain.

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But then, if we get down to the inferior

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aspect of the medulla oblongata,

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the left posterior aspect,

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we're seeing focal enlargement,

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and there's no associated abnormal enhancement.

1:03

So, while this could be a waxing and waning

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appearance of a lesion in NF 1

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and warrants observation,

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but given that there's a vocal cord paralysis,

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this definitely warrants very close follow-up.

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The problem in the brainstem is that

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this is not an easy place to be able to resect a lesion

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without resulting in more permanent neurologic deficits.

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If a lesion persists,

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it is possible to do a very focal biopsy.

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They use a biopsy not to just say,

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is it a tumor or not,

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but to get histologic and genetic

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characterization of the lesion,

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because there may be targeted chemotherapy

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for a specific genetic subtype.

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The lesions in neurofibromatosis type 1,

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histologically,

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are almost always pilocytic astrocytoma,

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even the solid infiltrating ones.

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And understanding its molecular profile

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can help with chemotherapy.

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So, they did not proceed to biopsy on this patient

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because it did not progress and

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the neurologic symptoms resolved.

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But that is something to be aware of.

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Also on this patient, when they were younger,

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we see this focal T2 hyperintense abnormality

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in the posterior orbital segment

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of the right optic nerve,

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and it looks different than the anterior orbital

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segment of the right optic nerve.

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That's a very subtle abnormality,

2:39

but it persists on this coronal image.

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See, perhaps slightly larger but also more

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hyperintense than T2 weighted imaging.

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Five years later,

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we see this asymmetric enlargement,

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fusiform enlargement of the orbital segment

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of the right optic nerve.

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So, this patient

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developed a right optic pathway glioma

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with fusiform enlargement of the optic nerve.

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And there is the lesion in the left posterior

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aspect of the medulla oblongata,

3:11

which did not progress.

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So while, histologically, it may be neoplasm,

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it did not warrant surgery,

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did not warrant biopsy,

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or did not warrant any other treatment,

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but did warrant close,

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continued imaging surveillance.